Cholesterol and transmitter release in crayfish neuromuscular junctions
Published: 2005
Place of publication: 2005
Language: eng
Format: Microform
Number of pages: 87
ISBN-13: 9780494164105
Description: The role of membrane lipids in the regulation of synaptic transmission is unclear. Cholesterol controls membrane fluidity and its depletion increased evoked exocytosis in pancreatic  -cells but decreased exocytosis in PC12 cells. I tested the effects of cholesterol depletion using methyl-beta cyclodextrin (M CD) and cholesterol addition using cholesterol-M CD (Ch-M CD) on synaptic transmission at the crayfish neuromuscular junction. M CD blocked evoked synaptic transmission but increased the frequency of spontaneous quantal release; both effects recovered when cholesterol was reintroduced. The increase in spontaneous release was not through a calcium dependent mechanism. Ch-M CD added alone also increased the frequency of spontaneous release. The shape of spontaneous events did not change significantly, suggesting a presynaptic mechanism. Focal extracellular recordings of individual boutons showed EPSP block was correlated with a failure of action potential at the boutons. In conclusion altering cholesterol levels in the presynaptic membrane modulates several key properties of synaptic transmission.
Notes: Source: Masters Abstracts International, Volume: 44-06.

Thesis (M.Sc.) -- University of Toronto, 2005.